Stabilized wax composition



Patented Jan. 13, 1953 STABILIZED WAX COMPOSITION j DavidfW. Young, Roselle, and Paul V. Smith, Jr.,

Westfield, N. J., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application December 29, 1949, Serial No. 135,846

8 Claims. (Cl. 106-270) CH3(CH2) PCHJ where a: is any integer.

Similarly, polyethylene has the formula where y is any oddnumbe'r. The presence of the ('CH2)y in the chain confers many of the properties of paraffin wax upon polyethylene and for this reason this material may be treated as a synthetic wax. The double bond at the end of the chain has relatively little effect on the properties f the molecule as a whole. Accordingly, any predominantly straight chain compound having a long chain consisting of a plurality of CH2- groups in a long chain will behave similarly to paraflin wax and is to be included within the scope of the present invention. Hereinafter long chain compounds having the above structure will be termed waxes.

Heat and light stability are important properties to consumers of wax depending on the use to be made of the wax. Many large wax consumers purchase wax in tank car lots. This wax must have reasonablestability so that it will not change color or odor appreciably during trans portation, reheating. at destination, intermediate tank storage and application on waxing machines at l60-200 F. Discolored and odoriferous waxes due to instability to heat and light during these periods prior to final use are often refused by the trade. Consequently specifications requiring both heat and light stable waxes are being set up by many large consumers.

While the efiect'of heat on the stability of waxes has been known for some time, it is only recently that the realization has been acquired that light is also a factor.

It is well known that certain 2,4,6-trialkylated phenols, such as 2,6 -di tertiary-butyl-4-methylphenol, are excellent heat stabilizers for waxes. However, most of them are of little, if any, importance as stabilizers for light.

It has now been found that the mono-, di-, and/or tri-ricinoleate esters of polyethylene glycol having the formula, HO(CH2CH2O)H, where n is an integer from 2 to 10, are outstanding agents for use in stabilizing waxes against deterioration by light. Since these materials are not good stabilizers against heat, it is necessary to incorporate a heat stabilizer in the wax along with the polyethylene glycol ricinoleate. Accordingly, the invention also proposes that a heat and light stable wax be prepared by the addition to wax of a 2,4,6-trialkylated phenol, such as 2,6-di-t-butyl-4-methylphenol as the heat stabilizer and the polyethylene glycol ricinoleate as the light stabilizer.

These stabilizing materials may be incorporated with the wax in any desired. amount, depending upon the conditions under which the material is to be used. If the conditions are harsh or severe, it is desirable to add a relatively large amount, while if the conditions are relatively mild, a very minute quantity will be sufiicient. The stabilizing material may be contained in the wax in a concentration of from 0.001% to 2% or higher. It is, however, preferred to add the material in concentrations from 0.01% to 1%.

The following examples illustrate the advantages of the present invention:

In these examples, the terminology polyethylene glycol di, tri-ricinoleate is employed to identify a particular ester and not to indicate a mixture of esters. The ester identified is esterified at each of the hydroxyl groups of the polyethylene glycol and the final ester contains three ricinoleic acid radicals at each of these positions on the polyethylene glycol molecule.

EXAMPLE 1 Various types of organic compounds were added in different proportions to refined hydrocarbon wax and the products tested for color and odor the blend was reduced 50%.

ture was heated to 153 C. until the viscosity of The time in hours Table 1 Inhibi- Fresh stock Heat stability 1 Light stability 1 orconc., x251; Color 3 Odor 4 Color 1 Odor Color 3 Odor W211i +30 8-. 1.0 l3 8.-" 3.0 -3 8-... 3.0

us: Dimethyl silicon polymer 0.01 ...d0... 1. 1.0 3.0 Octadecyl amine 01 -.do 2. 0 3. 0 3. 0 Do .10 ...do 2.0 3.0 3.0 2,6-ditertiary-butyl-4-methylphenol .01 +29 S" 1.0 1.5 3.0 Do .05 +28 S 1.0 1.5 3.0 Phenoxy propylene oxide 05 +30 3.0 3.0 2. 6 Organic Phosphite .2

Do 1. 0 Mono tert-butyl ether of hydroquinone. .2 +30 8.. 3.0 Do l. 0 +28 S 3. 0 Polyethylene glycol di,tri-ricinoleate 1 +24 8.. 1. 7 D0 5 +17 1. 2

l 16 hours at 302 F. in presence of copper; 0 Saybolt color or lighter and satisfactory odor is 3 23 hours under carbon arc in Weathcr-O-Meter; 0 Saybolt color or lighter and satisfactory o 3 SSaybolt; TR-Tag Robinson.

gassing.

or is passing.

4 Rating: 1, no or slight odor; 2, odor but not objectionable; 3, objectionable odor. 5 Reaction product of 2,6-di-tert-butyl-i-tert-octylphenyl ether of ethylene glycol with phosphorus trichloride.

6 Prepared from a polyethylene glycol having a molecular weight of 400.

The above data indicate that polyethylene glycol di-, tri-ricinoleate is an excellent stabilizer for wax against deterioration by light. At the same time the data show that such an excellent heat stabilizer as 2,6-di-t-butyl-4-methylphenol is a poor light stabilizer.

Example 2 In a second experiment, a parafiin wax with a melting point of 132 F., and an oil content of 0.2%. was melted at 160 F. and poured into a stainless steel mold, The mold was of such a size that slabs of wax were; made that had the following dimensions:

After the wax had cooled in a clean laboratory, it was removed from the mold. One half of each slab was well-wrapped in tin foil; The slab of wax was then placed in a window facing south. After a period of 14 days at room temperature the wax was evaluated for color and odor and the following results were obtained:

Table 2 Ex osed to Unexposed to ight Light Sample Color Odor Color Odor 1. Paraifinwax Light yellow Poor. White. Good. 2. Parafiin wax 0.4% White Good. .do Do.

polyethylene glycol di-, tririclnoleate 3. Parafiin wax 0.6% do do .do.. Do.

polyethylene glycol di-, tri-ricinoleate for the blend to reach 50% of its original viscosity is reported in the following data:

Table 3 Timein hours to reach 50% breakdown in viscosity Compound:

Original blend (blank) 7 2,6-di-t-butyl-4-methylphenol 325 Polyethylene glycol di-, tri-ricinoleate 6 Prepared from a polyethylene glycol having a molecular weight of 400.

Fresh wax 'Heat stability g Color Odor, Color 1 Odor vColor 4 Refined wax 1. 0 +30 S. l.

+243. 1.7 -1lTR. 3.0 +22S. 2.7

1 16 hours at 302 F. in prosonceof copper.-

1 23 hours exposure to carbon are. of Fade-O-Metcr.

{Ratuigz 1,, no or slight odor; 2, odor but not objectionable; 3, ob eetmnebIe odor. r

5 Prepared from a polyethylene glycolhaving a molecular weight The above data show that it is necessary to add both of these materials to the wax in order to obtain both heat and light stability.

EXAMPLE 5 0.6% diethylene glycol mono-ricinoleate, polyethylene glycol mono-ricinoleate, and polyethylene glycol, di-, tri-ricinoleate were tested in 7,000 and 12,000 molecular weight polyethylene by a 2 month exposure to direct sunlight. Slabs 6" x 6" X /z" were molded and half of it wrapped in tin foil prior to the sunlight exposure. At the end of the test, the exposed half of the control slab was light yellow while that under the tin foil remained white. In the case of the slab containing the esters, there were no differences between the color of the exposed and protected halves of the slab-both were white.

EXAIWPLE 6 Enamel plates were polished with two automobile waxes prepared from carnauba wax, 148 melting point parafiin wax, kerosene, and dye. One wax contained 0.01% by weight of 2,6-di-tbutyl-4-methylphenol and 0.1% by weight of polyethylene glycol di-, tri-ricinoleate and the other wax contained no stabilizer. The polished panels were allowed to age 11 weeks under outdoor exposure conditions. The panel polished with the wax containing the stabilizer was only slightly oxidized and still possessed good luster. The panel polished with the wax containing no stabilizer was found to be much duller than the other.

The above examples clearly show the effectiveness of the light stabilizing agents in long-chain wax-like hydrocarbon products such as polyethylene and parafiin wax and in car polishes containing wax. It is not completely satisfactory in blends of vinyl compounds with a copolymer of acrylonitrile and butadiene known as Paracril. It is completely inefiective in stabilizing spindle oils. The polyethylene glycol ricinoleates are unique in possessing the above properties since substances similar in structure, such as castor oil, pentaerythritol monostearate and ethylene glycol monostearate have been found to be ineffective as light stabilizers in these wax-like compositions.

The nature and objects of the present invention having been thus fully set forth and specific examples of the same given, what is claimed as new and useful and desired to be secured by Letters Patent is:

1. An improved normally solid wax-like composition consisting essentially of a substantially colorless wax-like hydrocarbon product chosen from the class consisting of paraffin wax and polyethylene and as a light stabilizing agent 0.01-1% of a ricinoleate ester of polyethylene glycol having the formula HO (CHZCHZO) 11H where n is an integer from 2 to 10.

2. Composition according to claim 1 in which the wax-like hydrocarbon product is paraffin wax.

3. Composition according to claim 1 in which the wax-like hydrocarbon product is polyethylene.

4. Composition according to claim 3 in which the light stabilizing agent is diethylene glycol mono-ricinoleate.

5. Composition according to claim 3 in which the light stabilizing agent is polyethylene glycol mono-ricinoleate.

6. Composition according to claim 3 in which the light stabilizing agent is polyethylene glycol di, tri-ricinoleate.

'7. An improved normal solid petroleum wax composition consisting essentially of a substantially colorless petroleum wax and as a light stabilizing agent 0.01 to 1% of a polyethylene glycol di, tri-ricinoleate in which the polyethylene glycol molecule, prior to esterification, has the formula HO(CH2CH20) 11H where n is an integer from 2 to 10.

8. An improved normally solid, light and heat stable petroleum wax composition comprising a substantially colorless petroleum wax, 0.01% to 1% of 2,6 di-t-butyl-4-methylphenol as a heat stabilizing agent and 0.01% to 1% of polyethylene glycol di, tri-rioinoleate as a light stabilizing agent in which the polyethylene glycol molecule, prior to esterification, has the formula HO (CI-IzCHzO) 11H where n is an integer from 2 to 10.

DAVID W. YOUNG. PAUL V. SMITH, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,210,140 Colbeth Aug. 6, 1940 2,301,806 Hamilton et a1 Nov. 10, 1942 OTHER REFERENCES Derivatives from Hydrogenated Castor Oil," Bell & Taub; Journal of American Pharmaceutical Asso., April 1943, pages -118.

Carbowax Compounds and Polyethylene Glycols, Carbide & Carbon Chem. Corp., New York, 1946, pages 3 and 10.

Polyethylene Glycol Esters, Kessler Chem. Co. Inc., 1948, pages 1 and 5. 

8. AN IMPROVE NORMALLY SOLID, LIGHT AND HEAT STABLE PETROLEUM WAX COMPOSITION COMPRISING A SUBSTANTIALLY COLORLESS PETROLEUM WAX, 0.01% TO 1% OF 2,6 DI-T-BUTYL-4-METHYLPHENOL AS A HEAT STABILIZING AGNET AND 0.01% TO 1% OF POLYETHYLENE GLYCOL, DI, TRI-RICINOLEATE AS A LIGHT STABILIZING AGENT IN WHICH THE POLYETHYLENE GLYCOL MOLECULE, PRIOR TO ESTERIFICATION, HAS THE FORMULA 